well, at least you've learned how to recognize pressed glass - although it doesn't always come with a diamond lozenge mark - the majority of pieces you will see have a just a number (accompanied with a trade mark, occasionally), and as the Readers Digest used to say ....'it pays to increase your word power', so time to get a few books Craig. Presumably you don't have any at present, so guess you're unable to decypher the data within the lozenge. Pressed glass has a big following here, so if you wish to know about your piece, tell us the details and someone is sure to be able to help. As you can imagine, compared to the potential value of an early C19 drinking glass made by The Cork Glass Company, this is rather a non starter, so hope you aren't too disappointed.